import panel as pn
pn.extension()

gspec = pn.GridSpec(width=800, height=600)

gspec[:,   0  ] = pn.Spacer(background='red',    margin=0)
gspec[0,   1:3] = pn.Spacer(background='green',  margin=0)
gspec[1,   2:4] = pn.Spacer(background='orange', margin=0)
gspec[2,   1:4] = pn.Spacer(background='blue',   margin=0)
gspec[0:1, 3:4] = pn.Spacer(background='purple', margin=0)

gspec

gspec.grid

gspec[2, 2]

gspec[0, 1:]

import holoviews as hv
import holoviews.plotting.bokeh

from bokeh.plotting import figure

fig = figure()
fig.scatter([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], [0, 1, 2, 3, 2, 1, 0, -1, -2, -3])

gspec = pn.GridSpec(sizing_mode='stretch_both', max_height=800)

gspec[0, :3] = pn.Spacer(background='#FF0000')
gspec[1:3, 0] = pn.Spacer(background='#0000FF')
gspec[1:3, 1:3] = fig
gspec[3:5, 0] = hv.Curve([1, 2, 3])
gspec[3:5, 1] = 'https://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png'
gspec[4:5, 2] = pn.Column(
    pn.widgets.FloatSlider(),
    pn.widgets.ColorPicker(),
    pn.widgets.Toggle(name='Toggle Me!'))

gspec